MIGRATION OF CU ADATOMS ON A CU(100) SURFACE, STUDIED WITH LOW-ENERGY ION-SCATTERING (LEIS)

We report the observation of adatoms appearing on the surface due to ion beam irradiation. These adatoms are interpreted to be self-interstitials, created in the damage cascades, which have diffused to the surface where they are trapped. From our LEIS experiments on a stepped Cu(100) surface we determined that on average 4.5(1.5) Cu adatoms per impinging ion reach the surface. The temperature at which Cu atoms on a Cu(100) surface become mobile was determined to be 140(5) K. This value was deduced from the temperature dependence of the Cu adatom yield.